In a typical air cooled condenser of a fuel, coal or gas-fired power station, steam flows into cooling tube arrays or bundles, which are cooled by a forced air flow. The arrays, which each form a generally flat, rectangular field, may be arranged at an angle in the range of 0 to 90 degrees with respect to the horizontal plane. For example, two arrays may be erected to form an A-shaped structure. The cooling tubes are fin tubes, i.e. tubes having cooling fins integrally mounted or formed thereon. The steam enters the cooling tubes in parallel flow from the top. Fans that are arranged below the structure draw ambient air and discharge it along the cooling tubes for cooling. The air crosses the tube arrays from below.
Because of the outdoor installation, and because the fans draw ambient air, dirt gradually accumulates on the cooling tube arrays. Resulting cooling performance deficits may involve performance deficits of the power station, so that cleaning is required. However, cleaning large cooling tube arrays manually using high-pressure cleaners is dangerous and hard labor. For example, ambient temperatures at the working area may even reach e.g. 60° C. to 70° C. A cooling tube array may have a height along the inclined direction of the tubes of e.g. 10 meters, and may extend over a length of e.g. 80 meters in the lateral direction. The inclination angle may, in particular, be 60° or more with respect to the horizontal.
U.S. Pat. No. 9,605,916 B2 describes a cleaning apparatus for cleaning a cooling tube array of a heat exchanger, including a triangular truss beam supported to be movable in a first direction, which direction is perpendicular to a longitudinal direction of the truss beam, a nozzle carriage movably held on the truss beam, the nozzle carriage being movable along the longitudinal direction of the truss beam, and a plurality of cleaning nozzles mounted to the nozzle carriage, the truss beam having two tubular top chords and one tubular bottom chord that is arranged centrally below the top chords, and bracings that connect the chords, and the nozzle carriage having at least one bottom chord roller that is arranged for traveling on the bottom side of the bottom chord; and a similar cleaning apparatus having a square truss beam. In an example, a motor that drives a pulley is mounted to the truss beam.
WO 2013/178353 A2 describes a cleaning apparatus for spraying cooling coils with water. The apparatus has travelling profiles that can be displaced over the cooling coils, and a carrying system for nozzles can be displaced along the travelling profiles. In one example, there are two C-shaped travelling profiles that are arranged with the opening facing upwards. A nozzle-carrying system engages the C-shaped profiles with arms and guide pieces. In another example, the travelling profiles are C-profiles or U-profiles, the openings of the profiles face each other, and the nozzle-carrying system has rollers engaging the profiles. The nozzle-carrying system is positioned between the profiles and is moved by a belt drive.
DE 10 2012 021 177 A1 and DE 10 2012 021 178 A1 describe cleaning devices having a travelling profile in the form of a truss beam. The truss beam has chord tubes and bracings connecting the chord tubes. A nozzle-carrying system is carried on the truss beam by pairs of rollers that travel on the chord tubes.
EP 1604164 B1 and DE 10 2009 052 676 A1 describe a mobile cleaning device for air cooled condensation units, in which a cleaning nozzle carrier is displaceable suspended from a square profile that is arranged such that a diagonal of the square is vertical. The carrier comprises rollers that travel on the flat sides of the square profile.
EP 2 317 274 A2 and DE 20 2010 017 403 U1 describe cleaning devices for a heat exchanger, with a ladder consisting of side walls and ladder rungs, to which two parallel arranged profiles are fastened, in or on which a nozzle holder is movable. In an example, the profiles are U-profiles that are arranged with their openings facing each other. The nozzle holder engages the U-profiles with rollers and hold the nozzle holder centrally between the U-profiles.
EP 2 317 273 A2 and DE 10 2010 010 011 A1 describe cleaning devices having a rectangular pipe profile, on which a nozzle holder is movably held by rollers.
U.S. Pat. No. 3,843,409 A describes a heat exchanger cleaning system having a boom. A cleaning head is supported on the boom by the cooperation of tracks mounted on the boom and a plurality of wheels mounted on the head.
U.S. Pat. No. 5,735,964 A describes an assembly for cleaning a tube bundle including a plurality of elongated tubular lances movable within an outer shell. A flexible fluid hose within the shell extends to the manifold in the lower portion of the assembly, which in turn transmits pressurized fluid to the plurality of lances. A hydraulic motor powers a rack and pinion assembly to reciprocate the lances. In an example, a hydraulic fluid line is provided for powering movement of the plurality of elongate tubular lances, and a flexible water pressure line is provided for transmitting pressurized water to the lances for conducting the cleaning operation.